Creation of Heterogeneous Cellulose Membranes by Multiple Solvent Replacement

Abstract

Cellulose is the most abundant biomass polymer in nature. Recently, cellulose nanofibers and composite- and functional-materials thereof are increasingly investigated. Additionally, the investigation about basics and applications of cellulose/ionic liquid solutions are also actively carried out. However, only membranes with a smooth surface structure similar to cellophane were obtained. We have dissolved cellulose in a mixed solution consisting of ionic liquid and organic solvent. We have evaluated the relationship between dissolution time and solution viscosity. By using a multiple solvent displacement method, we constructed a method to make heterogeneous membranes that were formed by spinodal decomposition. The membrane had a high specific surface area and thus, may be applied to high performance permeation membranes and separation membranes.